From c4adeee0e7b6505c9e1e4330572c4236f3586b73 Mon Sep 17 00:00:00 2001 From: Chong Yidong Date: Mon, 13 Apr 2009 15:54:17 +0000 Subject: [PATCH] * display.texi (Refresh Screen): Note that a passage about screen refreshing is text terminal only. (Forcing Redisplay): Delete misleading comment---sit-for calls redisplay, not the other way around. (Truncation): Note new values of truncate-partial-width-windows. Copyedits. (Invisible Text): Document invisible-p. --- doc/lispref/ChangeLog | 10 ++++ doc/lispref/display.texi | 103 +++++++++++++++++++++++---------------- 2 files changed, 71 insertions(+), 42 deletions(-) diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog index 58349355a0..bac2817b02 100644 --- a/doc/lispref/ChangeLog +++ b/doc/lispref/ChangeLog @@ -1,3 +1,13 @@ +2009-04-13 Chong Yidong + + * display.texi (Refresh Screen): Note that a passage about screen + refreshing is text terminal only. + (Forcing Redisplay): Delete misleading comment---sit-for calls + redisplay, not the other way around. + (Truncation): Note new values of truncate-partial-width-windows. + Copyedits. + (Invisible Text): Document invisible-p. + 2009-04-11 Eli Zaretskii * display.texi (Overlays): Overlays don't scale well. See diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi index a6c09cd0e3..8fa9a82c6e 100644 --- a/doc/lispref/display.texi +++ b/doc/lispref/display.texi @@ -60,11 +60,11 @@ you call these functions when input is available, they don't redisplay immediately, but the requested redisplay does happen eventually---after all the input has been processed. - Normally, suspending and resuming Emacs also refreshes the screen. -Some terminal emulators record separate contents for display-oriented -programs such as Emacs and for ordinary sequential display. If you are -using such a terminal, you might want to inhibit the redisplay on -resumption. + On text-only terminals, suspending and resuming Emacs normally also +refreshes the screen. Some terminal emulators record separate +contents for display-oriented programs such as Emacs and for ordinary +sequential display. If you are using such a terminal, you might want +to inhibit the redisplay on resumption. @defvar no-redraw-on-reenter @cindex suspend (cf. @code{no-redraw-on-reenter}) @@ -79,13 +79,13 @@ to redraw, @code{nil} means redrawing is needed. The default is @code{nil}. @cindex forcing redisplay Emacs normally tries to redisplay the screen whenever it waits for -input. With this function you can request an immediate attempt to -redisplay, in the middle of Lisp code, without actually waiting for -input. +input. With the following function, you can request an immediate +attempt to redisplay, in the middle of Lisp code, without actually +waiting for input. @defun redisplay &optional force This function tries immediately to redisplay, provided there are no -pending input events. It is equivalent to @code{(sit-for 0)}. +pending input events. If the optional argument @var{force} is non-@code{nil}, it does all pending redisplay work even if input is available, with no @@ -166,14 +166,12 @@ truncation; a @samp{\} on the rightmost column indicates a line that for this; @pxref{Display Tables}). @defopt truncate-lines -This buffer-local variable controls how Emacs displays lines that extend -beyond the right edge of the window. The default is @code{nil}, which -specifies continuation. If the value is non-@code{nil}, then these -lines are truncated. - -If the variable @code{truncate-partial-width-windows} is non-@code{nil}, -then truncation is always used for side-by-side windows (within one -frame) regardless of the value of @code{truncate-lines}. +If this buffer-local variable is non-@code{nil}, lines that extend +beyond the right edge of the window are truncated; otherwise, they are +continued. As a special exception, the variable +@code{truncate-partial-width-windows} takes precedence in +@dfn{partial-width} windows (i.e., windows that do not occupy the +entire frame width). @end defopt @defopt default-truncate-lines @@ -182,42 +180,50 @@ buffers that do not have buffer-local values for it. @end defopt @defopt truncate-partial-width-windows -This variable controls display of lines that extend beyond the right -edge of the window, in side-by-side windows (@pxref{Splitting Windows}). -If it is non-@code{nil}, these lines are truncated; otherwise, -@code{truncate-lines} says what to do with them. +This variable controls line truncation in @dfn{partial-width} windows. +A partial-width window is one that does not occupy the entire frame +width (@pxref{Splitting Windows}). If the value is @code{nil}, line +truncation is determined by the variable @code{truncate-lines} (see +above). If the value is an integer @var{n}, lines are truncated if +the partial-width window has fewer than @var{n} columns, regardless of +the value of @code{truncate-lines}; if the partial-width window has +@var{n} or more columns, line truncation is determined by +@code{truncate-lines}. For any other non-@code{nil} value, lines are +truncated in every partial-width window, regardless of the value of +@code{truncate-lines}. @end defopt When horizontal scrolling (@pxref{Horizontal Scrolling}) is in use in a window, that forces truncation. @defvar wrap-prefix -If this buffer-local variable is non-@code{nil}, the prefix it defines -will be added at display-time to the beginning of every continuation -line due to text wrapping (so if lines are truncated, the wrap-prefix -is never used). It may be a string, an image, or a stretch-glyph such -as used by the `display' text-property. @xref{Display Property}. - -A wrap-prefix may also be specified for regions of text using the -@code{wrap-prefix} text-property (which takes precedence over the -value of the @code{wrap-prefix} variable). @xref{Special Properties}. +If this buffer-local variable is non-@code{nil}, it defines a +``prefix'' that is added at display-time to the beginning of every +continuation line. (If lines are truncated, the wrap-prefix is never +used.) It may be a string, an image, or a stretch-glyph, as used by +the @code{display} text property. @xref{Display Property}. + +A wrap-prefix may also be specified for regions of text, using the +@code{wrap-prefix} text property. This takes precedence over the +value of the @code{wrap-prefix} variable. @xref{Special Properties}. @end defvar @defvar line-prefix -If this buffer-local variable is non-@code{nil}, the prefix it defines -will be added at display-time to the beginning of every -non-continuation line It may be a string, an image, or a stretch-glyph -such as used by the `display' text-property. @xref{Display Property}. +If this buffer-local variable is non-@code{nil}, it defines a +``prefix'' that is added at display-time to the beginning of every +non-continuation line. It may be a string, an image, or a +stretch-glyph, as used by the @code{display} text property. +@xref{Display Property}. A line-prefix may also be specified for regions of text using the -@code{line-prefix} text-property (which takes precedence over the -value of the @code{line-prefix} variable). @xref{Special Properties}. +@code{line-prefix} text property. This takes precedence over the +value of the @code{line-prefix} variable. @xref{Special Properties}. @end defvar If your buffer contains @emph{very} long lines, and you use -continuation to display them, just thinking about them can make Emacs -redisplay slow. The column computation and indentation functions also -become slow. Then you might find it advisable to set +continuation to display them, computing the continuation lines can +make Emacs redisplay slow. The column computation and indentation +functions also become slow. Then you might find it advisable to set @code{cache-long-line-scans} to @code{t}. @defvar cache-long-line-scans @@ -846,12 +852,25 @@ major mode should use the mode's own name as an element of (remove-from-invisibility-spec 'my-symbol) @end example + You can check for invisibility using the following function: + +@defun invisible-p pos-or-prop +If @var{pos-or-prop} is a marker or number, this function returns a +non-@code{nil} value if the text at that position is invisible. + +If @var{pos-or-prop} is any other kind of Lisp object, that is taken +to mean a possible value of the @code{invisible} text or overlay +property. In that case, this function returns a non-@code{nil} value +if that value would cause text to become invisible, based on the +current value of @code{buffer-invisibility-spec}. +@end defun + @vindex line-move-ignore-invisible Ordinarily, functions that operate on text or move point do not care whether the text is invisible. The user-level line motion commands -explicitly ignore invisible newlines if -@code{line-move-ignore-invisible} is non-@code{nil} (the default), but -only because they are explicitly programmed to do so. +ignore invisible newlines if @code{line-move-ignore-invisible} is +non-@code{nil} (the default), but only because they are explicitly +programmed to do so. However, if a command ends with point inside or immediately before invisible text, the main editing loop moves point further forward or -- 2.20.1